The present invention relates to an infrared signal transmission protocol and more particularly to an infrared signal transmission protocol for wireless keyboard and PC remote controller. The protocol identifies the codes transmitted corresponding to various statuses of either keys, or button or pointing device respectively on the wireless keyboard and PC remote controller.
Due to the need for wireless communication or control from a wireless keyboard and personal computer (PC) remote controller respectively, wireless keyboard or PC remote controller has been introduced into marketplace recently. As shown in FIG. 1, on the personal computer 11, a conventional infrared signal receiver 110, an I/O controller 113 having a standard RS-232 port are provided. For instance, the conventional infrared signal receiver 110 may be the type that decodes infrared signal of 940 nm with a 38 KHz carrier. In a well known manner, the output of the receiver 110 is received by the I/O controller 113 through the standard RS-232 port. The input device to the personal computer 11 may include the keyboard 13 and the PC remote controller 15. Either the keyboard 13 or the PC remote controller 15 is selectively connected to the personal computer 11 wirelessly. In typical, the keyboard 13 has a pointing device 130, i.e. mouse, and a plurality of keys thereon. In typical, the PC remote controller 15 has a plurality of buttons (functions) 151, i.e. CD, and a pointing device 153 thereon.
Under the configuration shown in FIG. 1, the present invention provides an infrared signal transmission protocol for the wireless keyboard and PC remote controller such that interference between the other audio/video electronic appliances and the wireless keyboard and PC remote controller are prevented. The transmission protocol provided by present invention not only allows to differentiate the transmission signals generated by the wireless keyboard and PC remote controller from those generated by controllers for other well known electronic appliances, but also encodes into the well known RS-232 format before transmitting to the receiver.
The communication protocol of the keyboard includes a MAKE code and a BREAK code.
The MAKE code is generated when one key is depressed and the BREAK code is generated when one key is released from a depressed condition.
The MAKE code includes a first data and a second data following the first data. The first data is formed by performing exclusive OR (XOR) operation over a parameter and a first ID code.
In a preferred embodiment, the parameter is obtained by summing a key number assigned to the key and a first predetermined constant.